author(s)
Saleh TA and Abdel-Gawad RM

abstract
The Egyptian cotton leaf worm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), is a serious polyphagous pest of cotton and other cultivated crops in Egypt. Therefore, the LC₅₀ of two insect growth regulators (IGRs), diflubenzuron and chromafenozide, were applied to the 2^nd and 4^th larval instars of S. littoralis to investigate their impacts on the total protein, carbohydrate and lipid contents of hemolymph and body homogenate of 6^th instar larvae. Moreover, native protein, glycoprotein, lipoprotein, isozymes and fractional protein were detected using electrophoresis. Diflubenzuron produced non-significant effect (p>0.05) on the hemolymph total protein content, significant (p<0.05) and a highly significant (p<0.01) decrease in body homogenate total protein content when larvae treated as 2^nd and 4^th instars, respectively. Conversely, chromafenozide treatment showed non-significant difference in total protein contents of the whole-body homogenate of treated larvae. The application of the two IGRs produced a highly significant reduction (P<0.01) on the hemolymph total carbohydrate and lipids. Also, the two IGRs resulted in general reduction on the whole body homogenate total carbohydrate and lipid contents of the treated larvae. The present investigation recorded that there were differences between control and treated larvae in native protein, glycoprotein, lipoprotein and SDS-protein bands. Also, the patterns of alcohol dehydrogenase, aldehyde oxidase, α-esterase and β-esterase showed more number of bands in treated larvae as compared with control. These unique bands could be considered as protein markers to discriminate among the treated larvae with chosen IGRs. Data presented in this work help to understand a part how Diflubenzuron and chromafenozide be effective in controlling S. littoralis.